I. Field of the Invention
This invention relates generally to line tapping and clamping devices and more particularly to a line tapping and clamping device for piercing a line of a refrigeration system to alter the level of the coolant contained therein.
II. Discussion of the Prior Art
A combination line tapping and clamping device must be small and adjustable to be used in the confined areas found in modern, compact refrigeration and air conditioning systems. The function of a line tapping and clamping device is to tap a tube or main line and tightly clamp a temporary branch or auxiliary line to the tube so high pressure fluid, such as freon, can be siphoned off or added without leakage. This prevents dangerous fluids from leaking into the atmosphere. Many line tapping and clamping devices, previously built, were incapable of simultaneously piercing a main line and clamping a branch line to the main line. These devices were also not built for use in the confined areas commonly found in modern refrigeration systems.
Simple clamping devices for coupling a branch line to a main line are well known in the prior art. These clamps are variations on a C-clamp having one arm fitting around the outside of a main line or tube and a second arm providing a seal and hole that aligns with a predetermined hole in the main line. Examples of this type of clamp can be found in U.S. Pat. Nos. 444,235, 915,230 and 4,157,195. In each of these patents, the hole extending through the wall of the main line must be present before the clamp is used to connect a branch line to the main line. No element for piercing the wall of the main line is present.
A simple line tapping device, described in U.S. Pat. No. 2,392,059, issued to O'Neil, is a C-clamp shaped device wherein the line of interest is cradled in one arm of the C-clamp and a threaded shaft, having a bit at one end, is threaded through the other arm of the C-clamp perpendicular to the line of interest. The threaded shaft is rotated to screw the bit through the line. The focus of the '059 patent is the ability of the device to tap the line and direct the fluid or gas flow down, in a controlled manner. Once the hole is made through the line and the bit is removed, the fluid or gas contained therein is free to flow out of the line through the hole. The device in the '059 patent is not designed to clamp a branch line to the main line and guide the fluid or gas in the line through a hose or branch line. Of course, the bit described in the '059 patent is solid and does not permit fluid or gas to flow through it. The device described in the '059 patent also does not have an adjustable handle for manipulating or moving the line tapping device into a confined area and holding the tapping device firmly while torque is applied for drilling the hole.
Devices incorporating the ability to clamp a line or pipe and pierce the pipe are described in U.S. Pat. Nos. 3,115,889, 3,547,144 and 3,648,725. Each of these patents disclose a clamp for securely clamping a valve to a section of conduit or pipe. Incorporated into each clamp and valve assembly is a needle or tapered hollow tube that can be forced through the wall of the pipe being clamped. Wrenches and screw drivers are used to securely fasten each clamp to the main pipe and to force the needle through the pipe. The problem with using these devices on a refrigeration system is apparent from the means used for clamping them to the main pipe and the means used for forcing the needle or tapered hollow tube through the wall of the pipe. The permanent nature of the fixtures once attached and the inability of the devices to be easily installed in a confined area make them cumbersome to use.
A device with problems similar to these is described in U.S. Pat. No. 1,812,907, issued to one William Tell. The device described in Tell is first clamped around a pipe, which requires the use of an auxiliary tool for rotating a bolt. A drill bit is then rotated to drill a hole in the pipe. Rotation of the drill bit also requires using an auxiliary tool. Finally, after the hole is tapped, the hollow drill bit is secured in place with a threaded sleeve. An auxiliary tool is also used to turn the threaded sleeve. Use of an auxiliary tool in a confined area is very cumbersome at best. If the Tell device is used to tap a pipe, an auxiliary tool must be used three times.
In contrast, the present invention is self-contained, in that no auxiliary tools are required to pierce a tube or pipe and secure a hollow needle to the pierced tube. Instead, a hand rotated disk member is provided for forcing a hollow needle through the tube or line of interest. The hole is not drilled but pierced in the line of interest. At essentially the same time as the piercing occurs, the line of interest is clamped in place and the hollow needle is secured to the line. This requires one motion and no extra tools, as opposed to three motions and three extra tools if the device described in Tell is used.
Other tools developed for overcoming the problem of working in a confined area include vice grip style devices. Using these devices, as shown in U.S. Pat. Nos. 3,395,724 and 3,698,419, a pipe is pierced either as the vice grips close or by squeezing a third handle having a bit. One problem with these devices is the inability to adjust the vice grips handles in relation to the direction of the pipe being tapped. In a confined area, it is possible that the pipe will be in such a position that the handles of the vice grips will not allow the jaws to be securely clamped around the pipe. Also, if a thick walled pipe is encountered, the user may not be able to apply enough force to pierce the pipe with these devices. The force that can be applied on the jaws of the vice grips is limited by the lever arm of the vice grip handles and the force applied by squeezing the handles. This force may be further limited by the inability to get one or both hands into the confined area. To improve upon these devices, the present invention uses an adjustable handle and a rotatable threaded member or forcing means including a disk member.
By adjusting the handle, the present invention can be made to fit into a confined area. Further, by using the threaded member or forcing means to apply force while holding the adjustable handle, a large amount of force can be applied to the piercing element to pierce the line of interest. The present invention also has a slidable hollow outer shaft to allow the clamp arms to be easily opened to fit around a variety of pipe sizes.
Other devices having easily opened clamp arms include drill jigs as described in U.S. Pat. No. 2,418,234, issued to McCullough and shown in Swiss Patent No. 426,430, disclosed by Homberger. These devices have two clamp arms that secure a piece of material, such as a pipe, in place for having a hole drilled in it. The drill bit and mechanism for turning the drill bit are separate devices that must be provided to tap a hole in the clamped material. No hand rotatable threaded member or forcing means including a disk member for forcing a needle through a pipe and simultaneously clamping the material in place is shown in these disclosures.
One other reference of interest is U.S. Pat. No. 4,342,338, issued to Glennie, which discloses a sealing boot for repairing a ruptured main and an application tool for applying the boot to the ruptured main. The application tool comprises upper and lower clamp jaws attached to upper and lower stems, a crank with a handle grip and a threaded shaft. The jaws extend perpendicularly from their respective stems and lie in face to face relation with one another. The jaws are maintained in such relation by the square shape of the lower stem slidably inserted into the square shaped bottom of the upper stem. The threaded shaft is mated through the threaded inner core of the top portion of the upper stem to the top end of the lower stem. The crank and hand grip are rotatably connected to the top end of the threaded shaft.
In operation, the operator grips the handle and rotates the crank. As the crank is rotated, the lower stem is moved upwardly or downwardly relative to the upper stem so that the upper and lower jaws are opened or closed. The device described in the '338 patent does not have a piercing element or an adjustable handle for using the device in a confined area.
From the above, it can be seen that the references of the related art, of which the present applicants are aware, individually and as a whole, fail to disclose a clamping assembly for simultaneously piercing and clamping a line of interest wherein the clamping assembly has a threaded member for applying a large amount of force to the piercing element, a slidable tube member for easily inserting the device around the pipe to be tapped, or an adjustable handle for maneuvering and holding the device.